Information recording apparatus and method, and information recording medium

ABSTRACT

An information recording apparatus for recording information onto an information recording medium having a plurality of recording layers, by irradiating the information recording medium with laser light for recording, the information recording apparatus including: a setting device for setting a preferable irradiation condition of the laser light which is preferable to one recording layer in which the information is scheduled to be recorded, out of the plurality of recording layers, for each recording state of another recording layer out of the plurality of recording layers; and an irradiating device for irradiating the one recording layer with the laser light in the set preferable irradiation condition.

TECHNICAL FIELD

The present invention relates to an information recording apparatus,such as a DVD recorder, an information recording method, and aninformation recording medium, such as a DVD.

BACKGROUND ART

This type of information recording apparatus is constructed to recordinformation by laser light for recording with a pulse width, pulseintensity, a pulse shape, recording strategy, or the like which arepreferable (referred to as a “preferable irradiation condition” in thisapplication as occasion demands) in accordance with the recording layerof the information recording medium, such as an optical disc.

Here, as described in a patent document 1 or the like, there is alsodeveloped an information recording medium, such as a multiple layer ormultilayer type, or dual layer type optical disc, in which a pluralityof recording layers are stacked or laminated on the same substrate. Theinformation recording apparatus firstly performs the recording withrespect to a recording layer located on the top, and secondly performsthe recording with respect to a recording layer located on the secondtop, in the preferable irradiation condition defined for such amultilayer type information recording medium.

Patent document 1: Japanese Patent Application Laying Open NO.2000-311346

DISCLOSURE OF INVENTION Object to be Solved by the Invention

However, if the recording is performed on the above-mentioned multilayertype information recording medium, the laser light reaches the otherrecording layers other than one recording layer located on the front asviewed from the irradiation side of the laser light, through at leastone recording layer, and a semitransparent reflective film, an adhesivefilm, or a middle film, or the like accompanied by the one recordinglayer. Moreover, the light reflected here is also detected by an opticalpickup through the one recording layer or the like. Thus, in the otherrecording layers, light transmittance, amount of residual aberration,layer damage, or the like varies depending on whether or not theinformation is recorded in at least one recording layer located on thecloser side than the other recording layers, i.e., depending on whetheror not there is a recording mark in an optical path by phase changerecording or irreversible change recording by heat or the like.Therefore, the preferable irradiation condition with respect to theother recording layers depends on the recording condition of at leastone recording layer located on the closer side than the other recordinglayers. As described above, in the case where there is a difference inthe preferable irradiation condition of each recording layer due to therecording condition in the other recording layers, if the preferableirradiation condition, such as an optimum recording pulse width, isdefined for each information recording medium or for each recordinglayer, as described in the above-mentioned Background Art, theirradiation condition of the laser light is not always optimum norpreferable, which is a technical problem. Moreover, there can beconsidered such an application or specification that it is advantageousif a recording layer on the upper layer side and a recording layer onthe lower layer side positively have a difference in the preferableirradiation condition. Even in this case, if the preferable irradiationcondition, such as an optimum recording pulse width, is defined for eachinformation recording medium, as in the above-mentioned Background Art,the irradiation condition of the laser light is not always optimum norpreferable.

In order to solve the above-mentioned conventional problem, it istherefore an object of the present invention to provide an informationrecording apparatus and an information recording method which can recordinformation while maintaining an appropriate irradiation condition oflaser light for recording, in each recording layer of a multilayer typeinformation recoding medium, for example, as well as the multilayer typeinformation recording medium.

Means for Solving the Object

In order to solve the above-mentioned object, an information recordingapparatus according to claim 1 of the present invention is aninformation recording apparatus for recording information onto aninformation recording medium provided with a plurality of recordinglayers, by irradiating the information recording medium with laser lightfor recording, the information recording apparatus provided with: asetting device for setting a preferable irradiation condition of thelaser light which is preferable to one recording layer in which theinformation is scheduled to be recorded, out of the plurality ofrecording layers, for each recording state of another recording layerout of the plurality of recording layers; and an irradiating device forirradiating the one recording layer with the laser light in the setpreferable irradiation condition.

In order to solve the above-mentioned object, an information recordingmethod according to claim 13 of the present invention is an informationrecording method of recording information onto an information recordingmedium provided with a plurality of recording layers, by irradiating theinformation recording medium with laser light for recording, theinformation recording method provided with: a setting process of settinga preferable irradiation condition of the laser light which ispreferable to one recording layer in which the information is scheduledto be recorded, out of the plurality of recording layers, for eachrecording state of another recording layer out of the plurality ofrecording layers; and an irradiating process of irradiating the onerecording layer with the laser light in the set preferable irradiationcondition.

In order to solve the above-mentioned object, an information recordingmedium according to claim 14 of the present invention is an informationrecording medium provided with a plurality of recording layers to recordtherein information by irradiating the information recording medium withlaser light for recording, wherein at least one of the plurality ofrecording layers has a management information area in which preferableirradiation condition information is recorded, in which the preferableirradiation condition information is to define a preferable irradiationcondition of the laser light which is preferable to one recording layerin which the information is scheduled to be recorded, out of theplurality of recording layers, for each recording state of anotherrecording layer out of the plurality of recording layers.

In order to solve the above-mentioned object, an information recordingmedium according to claim 15 of the present invention is An informationrecording medium, provided with a plurality of recording layers torecord therein information by irradiating the information recordingmedium with laser light for recording, and having a first test writingarea in which the information is recorded in another recording layer outof the plurality of recording layers and a second test writing area inwhich the information is not recorded in the another recording layer, inorder to obtain a preferable irradiation condition of the laser lightwhich is preferable to one recording layer in which the information isscheduled to be recorded, out of the plurality of recording layers.

These effects and other advantages of the present invention become moreapparent from the following embodiments and example.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] FIG. 1 shows the basic structure of an optical disc accordingto an example of the information recording medium of the presentinvention, wherein the upper part is a substantial plan view showing theoptical disc having a plurality of areas and the corresponding lowerpart is a schematic conceptual view showing a recording area structurein the radial direction.

[FIG. 2] FIG. 2 is a partially enlarged perspective view showing arecording surface of the optical disc according to the example of theinformation recording medium of the present invention.

[FIG. 3] FIG. 3 is a data structural view conceptually showing anexample of the data structure of the optical disc according to theexample of the information recording medium of the present invention.

[FIG. 4] FIG. 4 is a table showing the classification of data of landpre-pits recorded in a lead-in area in an L1 layer of the optical discaccording to the example of the information recording medium of thepresent invention.

[FIG. 5] FIG. 5 is a table showing the arrangement and the ECC blockaddress in the lead-in area of the land pre-pits in the L1 layer of theoptical disc according to the example of the information recordingmedium of the present invention.

[FIG. 6] FIG. 6 is a schematic conceptual view showing a relationshipbetween laser light for recording and the optical disc in the case wherean L0 layer is unrecorded on the optical disc according to a firstexample of the information recording apparatus of the present invention.

[FIG. 7] FIG. 7 is a schematic conceptual view showing the relationshipbetween the laser light for recording and the optical disc in the casewhere the L0 layer is recorded on the optical disc according to thefirst example of the information recording apparatus of the presentinvention.

[FIG. 8] FIG. 8 is a graph showing a recording pulse characterized bypulse intensity which is one specific example of a preferableirradiation condition according to the first example of the informationrecording apparatus of the present invention.

[FIG. 9] FIG. 9 is a graph showing a recording pulse characterized by apulse width which is another specific example of the preferableirradiation condition according to the first example of the informationrecording apparatus of the present invention.

[FIG. 10] FIG. 10 is a graph showing a recording pulse characterized bythe pulse intensity and the pulse width which are another specificexample of the preferable irradiation condition according to the firstexample of the information recording apparatus of the present invention.

[FIG. 11] FIG. 11 is a schematic conceptual view showing therelationship between the laser light for recording and the optical discin the case where the L0 layer is unrecorded on the optical discaccording to a second example of the information recording apparatus ofthe present invention.

[FIG. 12] FIG. 12 is a schematic conceptual view showing therelationship between the laser light for recording and the optical discin the case where the L0 layer is recorded on the optical disc accordingto the second example of the information recording apparatus of thepresent invention.

[FIG. 13] FIG. 13 is a block diagram showing an informationrecording/reproducing apparatus in an example of the informationrecording apparatus of the present invention.

[FIG. 14] FIG. 14 is a flowchart showing a recording operation of theoptical disc in the example of the information recording apparatus ofthe present invention.

DESCRIPTION OF REFERENCE CODES

-   1 Center hole-   10 Track-   11 ECC block-   100 Optical disc-   101-0 (101-1) Lead-in area-   101A-0 (101A-1) OPC area-   101B-0 (101B-1) Management information recording area-   101C-0 (101C-1) Preferable information upon not-recording-   102-0 (102-1) Data zone-   103-0 (102-1) Lead-out area-   106 Transparent substrate-   107 First recording layer-   109 Wobble-   108 Semitransparent reflective film-   205 Middle layer-   207 Second recording layer-   208 Reflective film-   300 Information recording/reproducing apparatus-   306 Data input/output control device-   307 Operation control device-   310 Operation button-   311 Display panel-   351 Spindle motor-   352 Optical pickup-   353 Signal recording/reproducing device-   354 CPU (drive control device)-   355 Memory-   GT Groove track-   LT Land track-   LB Laser light-   LP Land pre-pit-   Lw1 First recording pulse-   Lw2 Second recording pulse-   Tc1 Time interval of cooling pulse-   Tmp Time interval of multi pulse-   Ttop Time interval of top pulse

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment of Information Recording Apparatus)

The information recording apparatus according to an embodiment of thepresent invention will be explained.

The embodiment of the information recording apparatus of the presentinvention is an information recording apparatus for recordinginformation onto an information recording medium provided with aplurality of recording layers, by irradiating the information recordingmedium with laser light for recording, the information recordingapparatus provided with: a setting device for setting a preferableirradiation condition of the laser light which is preferable to onerecording layer in which the information is scheduled to be recorded,out of the plurality of recording layers, for each recording state ofanother recording layer out of the plurality of recording layers; and anirradiating device for irradiating the one recording layer with thelaser light in the set preferable irradiation condition.

According to the information recording apparatus of the presentinvention, the information is recorded onto the multilayer typeinformation recording medium in which the plurality of recording layersare stacked or laminated on one side of a substrate, such as amultilayer or dual layer or multiple layer type optical disc, byirradiating the information recording medium with the laser light.Particularly in the embodiment, by the setting device including a CPU(Central Processing Unit) or the like, for example, the preferableirradiation condition of the laser light which is preferable to onerecording layer in which the information is scheduled to be recorded(e.g. an L1 layer described later) is set for each recording state ofanother recording layer or another recording layers (e.g. an L0 layerdescribed later). Here, the expression, “for each recording state”,means in accordance with in which recording state it is, out of aplurality of recording states whose presence is premised in one or aplurality of recording layers, including a recorded state, an unrecordedstate, a partially recorded state, a partially unrecorded state or thelike. Typically, the expression means for each difference of whether itis unrecorded or recorded. For example, in one recording layer, thereare two combinations of whether to be recorded or unrecorded. Moregenerally, in n pieces of recording layers (n is a natural number of 2or more), there are the n-th power of two pieces of combinations ofwhether to be unrecorded or recorded. After that, by the irradiatingdevice including a semiconductor laser or the like, the one recordinglayer (e.g. the L1 layer) is irradiated with the laser light, in thepreferable irradiation condition set in the above manner. At this time,the irradiating device modulates the laser light in accordance with theinformation to be recorded. For example, the irradiating device performspulse width modulation, pulse intensity modulation, or the like. At thistime, recording strategy is also preferably optimized.

Particularly, here, if another recording layer is located on the frontof one recording layer, as viewed from the irradiation side of the laserlight (e.g. in the case that the another recording layer is the L0layer), light transmittance and the amount of residual aberration in therecording of the one recording layer varies in each recording state ofthe another recording layer. Alternatively, if another recording layeris located on the rear of one recording layer, as viewed from theirradiation side of the laser light (e.g. in the case that the anotherrecording layer is the L1 layer or an L2 layer, etc.), an influence oflayer damage or the like varies in each recording state of the anotherrecording layer. Therefore, in any cases, the preferable irradiationcondition related to the laser light for recording, such as the pulsewidth, the pulse intensity, the pulse shape, and the recording strategy,generally varies depending on each recording state of the anotherrecording layer.

However, in the embodiment, the preferable irradiation condition is setby the setting device for each recording state of another recordinglayer, as described above, so that it is possible to individually setthe preferable irradiation condition of the laser light even in anyrecording state of another recording layer. The embodiment is differentfrom the above-mentioned background art in which the preferableirradiation condition is uniquely defined regardless of the recordingstate of another recording state, therefore owing to the embodiment, ifanother recording layer is in a certain recording state, the informationcan be recorded with an extremely notable difference and in a goodcondition.

As described above, according to the embodiment, it is possible toirradiate the laser light in the preferable irradiation condition,regardless of the recording state, which is recorded or unrecorded orthe like, of another recording layer, such as the recording layerlocated on the front as viewed from the irradiation side of the laserlight. By this, it is possible to record the information in a goodcondition, onto the multilayer type information recording medium,regardless of its recording state.

Incidentally, normally, the information is recorded into a recordingarea with a certain areal (or area) size in all the recording areas.Thus, the preferable irradiation condition may be changed in accordancewith the recording state, which is recorded or unrecorded or the like,of another recording layer, during the recording. In other word, inrecording the information, the preferable irradiation condition may bechanged by the setting device, as occasion demands. On the other hand,the information is recorded into a partial recording area in all therecording areas. Thus, a judgment of whether another recording layer isrecorded or unrecorded may be performed during the recording orfrequently, and as a result, the preferable irradiation condition may bechanged during the recording or frequently.

In one aspect of the embodiment of the information recording apparatusof the present invention, the setting device sets at least one of apulse width, pulse intensity, a pulse shape, and recording strategy ofthe laser light, which are preferable to the one recording layer.

According to this aspect, at least one of the pulse width, the pulseintensity, the pulse shape, and the recording strategy, which arepreferable to the one recording layer, is set by the setting device, foreach recording state of another recording layer. Therefore, it ispossible to record the information in a good condition by using thelaser light, onto the multilayer type information recording medium,regardless of its recording state.

In another aspect of the embodiment of the information recordingapparatus of the present invention, the information recording apparatusis further provided with a judging device for judging a difference ofwhether the another recording layer is unrecorded or recorded, as foreach recording state, and the setting device sets the preferableirradiation condition, in accordance with a judgment result by thejudging device.

According to this aspect, if the information is recorded, at first, thedifference of whether the another recording layer is unrecorded orrecorded is judged by the judging device including a CPU, an opticalpickup or the like, for example. Then, in accordance with the judgmentresult, the preferable irradiation condition is set by the settingdevice. Therefore, in performing the recording with respect to onerecording layer, it is possible to certainly judge the difference of therecording state in another recording layer, and further, on the basis ofthis, it is possible to perform the recording by using the laser lightin the preferable irradiation condition which is preferable to the onerecording layer.

In an aspect associated with the judging device, the judging device mayjudge the difference of whether or not the another recording layer isunrecorded or recorded, by each predetermined area unit, by collectivelyscanning recording areas in the another recording layer, before theinformation is recorded into the one recording layer.

By such construction, the recording areas of another recording layer arecollectively scanned by the judging device, and the difference ofwhether the another recording layer is unrecorded or recorded is judgedby each predetermined area unit. For example, a plurality of pointswhich are spread in all the recording areas are accessed, and thedifference of whether or not the another recording layer is unrecordedor recorded is judged at each of the accessed points. In this case, the“area unit” is preferably a size determined according to the amount ofinformation to be recorded in the following series of recordingoperation or operations. Alternatively, in view of frequency ofperforming such a judgment operation by the judging device, it may beequal to or greater than, or equal to or less than the size according tothe amount of the information to be recorded. With respect to thejudgment of whether to be unrecorded or recorded in each area unit, forexample, a ratio between an unrecorded areal (or area) size and arecorded areal size, a ratio between the number of unrecorded tracks andthe number of recorded tracks, or the like is detected, and this ratioor these ratios are compared with a predetermined reference(predetermined threshold value), to thereby judge it is “(to be treatedas) unrecorded” or “(to be treated as) recorded”. The predeterminedthreshold value in this case may be variably set in accordance with aninterlayer distance between one recording layer and another recordinglayer.

Incidentally, in the case of a DVD-R, for example, the information iswritten in order from the inner circumferential side of the disc in therecording area, so that an unrecorded area can be easily specified.

In an aspect associated with the judging device, the judging device mayjudge the difference of whether or not the another recording layer isunrecorded or recorded, by referring to table information whichindicates the difference of whether or not the another recording layeris unrecorded or recorded, by each predetermined area unit in recordingareas in the another recording layer.

By such construction, a table is referred to by the judging device, andthe difference of whether the another recording layer is unrecorded orrecorded is judged, easily and quickly, by each predetermined area unit.Such a table may be stored in a storage apparatus mounted on theinformation recording apparatus side, or may be recorded in a managementinformation area of the information recording medium side.

In another aspect of the embodiment of the information recordingapparatus of the present invention, at least one of the plurality ofrecording layers has a management information area in which preferableirradiation condition information for defining the preferableirradiation condition for each recording state of the another recordinglayer, is recorded, the information recording apparatus is furtherprovided with a first reading device for reading the preferableirradiation condition information from the management information area,and the setting device sets the preferable irradiation condition on thebasis of the read preferable irradiation condition information.

According to this aspect, in at least one of the plurality of recordinglayers, the preferable irradiation condition information is recorded inthe management information area which is in or near a lead-in area, forexample. Such preferable irradiation condition information may berecorded as pre-format information, such as a pre-pit, in advance, ormay be recorded as the preferable irradiation condition informationwhich is separately generated through the setting operation performed bythe setting device. Upon the operation of the information recordingapparatus, at first, the preferable irradiation condition information isread from the management information area by the reading deviceincluding an optical pickup or the like, for example. Then, thepreferable irradiation condition is set by the setting device, on thebasis of the read preferable irradiation condition information.

Alternatively, in another aspect of the embodiment of the informationrecording apparatus of the present invention, the information recordingapparatus is further provided with: a test-writing controlling devicefor controlling the irradiating device to test-write data for testwriting into the one recording layer, in both (i) an unrecorded area inwhich the another recording layer is unrecorded and (ii) a recorded areain which the another recording layer is recorded; and a second readingdevice for reading the data for test writing, from the one recordinglayer in both the unrecorded area and the recorded area in which thetest writing is performed, and the setting device sets the preferableirradiation condition, on the basis of the read data for test writing.

According to this aspect, before the information is recorded in onerecording layer, the data for test writing is test-written into the onerecording layer, in both the unrecorded area and the recorded area inanother recording layer, under the control of the test-writingcontrolling device. For example, so-called OPC (Optimum PowerCalibration) or the like is performed. After that, the data for testwriting is read by the reading device from the one recording layer inthe unrecorded area and the recorded area in which the test writing hasbeen performed. Then, the preferable irradiation condition is set by thesetting device on the basis of the read data for test writing.Therefore, it is possible to set the preferable irradiation conditionwhich reflects the actual state of the recording layer in real time, onthe basis of the data for test writing.

In this aspect, the information recording apparatus may be furtherprovided with a first storing device for storing preferable irradiationcondition information which indicates the preferable irradiationcondition set by the setting device.

By such construction, the preferable irradiation condition information,obtained by using the test writing process which requires a relativelylong time and a relatively heavy processing load, is maintained on theinformation recording apparatus side, to thereby allow the effective usethereof.

However, the preferable irradiation condition information set by usingthe test writing process as described above may be also recorded in themanagement information area of the information recording medium, asdescribed above.

Alternatively, in another aspect of the embodiment of the informationrecording apparatus of the present invention, at least one of theplurality of recording layers has a management information area in whichpreferable irradiation condition information for defining the preferableirradiation condition in only one of (i) a case where the anotherrecording layer is unrecorded and (ii) a case where the anotherrecording layer is recorded, is recorded, the information recordingapparatus is further provided with a third reading device for readingthe preferable irradiation condition information from the managementinformation area, and the setting device sets the preferable irradiationcondition on the basis of the read preferable irradiation conditioninformation in the one case, and sets the preferable irradiationcondition on the basis of (I) the read preferable irradiation conditioninformation and (II) relationship information which indicates a relativerelationship between a preferable irradiation defined for the other caseand a preferable irradiation condition defined for the one case, in theother case out of the unrecorded case and the recorded case.

According to this aspect, in at least one of the plurality of recordinglayers, the preferable irradiation condition information is recorded inthe management information area which is in or near a lead-in area, forexample. Such preferable irradiation condition information is defined inonly one of (i) the case where the another recording layer is unrecordedand (ii) the case where the another recording layer is recorded. Uponthe operation of the information recording apparatus, at first, thepreferable irradiation condition information is read from the managementinformation area by the reading device including an optical pickup orthe like, for example. Then, the preferable irradiation condition is setby the setting device, on the basis of the read preferable irradiationcondition information and the relationship information.

In an aspect associated with the relationship information, thepreferable irradiation condition may be expressed as a predeterminedparameter value related to the laser light, and the relationshipinformation may include information which indicates a ratio ordifference of the predetermined parameter value in the other case, withrespect to the predetermined parameter value in the one case.

By such construction, for example, as one example of the predeterminedparameter value, if the pulse width of the laser light is D1 in the casewhere the another recording layer is unrecorded and the pulse width ofthe laser light is D2 in the case where the another recording layer isrecorded, the relationship information is information which represents aratio c=D2/D1 and a difference .=D2.D1. Then, even if the pulse width D2of the laser light which is the preferable irradiation condition in thecase where the another recording layer is recorded, is unknown, it canbe set, like D2=c×D1, D2=D1+., or the like.

In an aspect associated with the relationship information, therelationship information may be recorded in the management informationarea together with the preferable irradiation condition information.

By such construction, when the information is recorded into onerecording layer, at first, by reading the preferable irradiationcondition information and the relationship information from themanagement information area, it is possible to set the preferableirradiation condition, easily and quickly, whether the another recordinglayer is unrecorded or recorded.

In an aspect associated with the relationship information, theinformation recording apparatus may be further provided with a secondstoring device for storing the relationship information, and the settingdevice may set the preferable irradiation condition, on the basis of theread preferable irradiation condition information and the relationshipinformation stored in the second storing device, in the other case.

By such construction, when the information is recorded into onerecording layer, at first, by virtue of the preferable irradiationcondition information read from the management information area and therelationship information read from the storing device, it is possible toset the preferable irradiation condition, easily and quickly, whetherthe another recording layer is unrecorded or recorded.

(Embodiment of Information Recording Method)

Next, the information recording method according to an embodiment of thepresent invention will be explained.

The embodiment of the information recording method of the presentinvention is an information recording method of recording informationonto an information recording medium provided with a plurality ofrecording layers, by irradiating the information recording medium withlaser light for recording, the information recording method providedwith: a setting process of setting a preferable irradiation condition ofthe laser light which is preferable to one recording layer in which theinformation is scheduled to be recorded, out of the plurality ofrecording layers, for each recording state of another recording layerout of the plurality of recording layers; and an irradiating process ofirradiating the one recording layer with the laser light in the setpreferable irradiation condition.

According to the embodiment of the information recording method of thepresent invention, as in the case of the above-mentioned informationrecording apparatus of the present invention, it is possible toirradiate the laser light in the preferable irradiation condition,regardless of the recording state, which is recorded or unrecorded orthe like, of another recording layer, such as the recording layerlocated on the front as viewed from the irradiation side of the laserlight. By this, it is possible to record the information in a goodcondition, onto the multilayer type information recording medium,regardless of its recording state.

(Embodiments of Information Recording Medium)

Next, the information recording medium according to embodiments of thepresent invention will be explained.

A first embodiment of the information recording medium of the presentinvention is an information recording medium provided with a pluralityof recording layers to record therein information by irradiating theinformation recording medium with laser light for recording, wherein atleast one of the plurality of recording layers has a managementinformation area in which preferable irradiation condition informationis recorded, in which the preferable irradiation condition informationis to define a preferable irradiation condition of the laser light whichis preferable to one recording layer in which the information isscheduled to be recorded, out of the plurality of recording layers, foreach recording state of another recording layer out of the plurality ofrecording layers.

According to the first embodiment of the information recording medium ofthe present invention, at least one of the plurality of recordinglayers, which are stacked or laminated on one side of a substrate, i.e.,which constitute the multilayer type information recording medium, suchas a multilayer type or dual layer or multiple layer type optical disc,for example, has the management information area in or near a lead-inarea located near the inner circumference. In the management informationarea, the preferable irradiation condition information is recorded,wherein the preferable irradiation condition information is to definethe preferable irradiation condition of the laser light for recording,for each recording state of another recording layer out of the pluralityof recording layers. The preferable irradiation condition informationmay be recorded from the beginning of the production of the informationrecording medium, or may be recorded upon subsequent pre-formatting orformatting. Alternatively, before the information is recorded, the valueof default may be recorded in the management information area, and then,it may be updated by a non-default value.

Incidentally, the preferable irradiation condition information may bedirectly defined, or indirectly defined, for example, by defining itwith a coefficient based on one irradiation condition (e.g. the pulsewidth).

Since the preferable irradiation condition information is recorded inthe management information area in this manner, upon the recordingthereof, performed by the information recording apparatus, such as anoptical disc recorder, at first, the preferable irradiation conditioninformation is read. Then, on the basis of the preferable irradiationcondition information, it is possible to irradiate the laser light inthe preferable irradiation condition, regardless of the recording state,which is recorded or unrecorded or the like, of another recording layer,such as the recording layer located on the front as viewed from theirradiation side of the laser light. By this, it is possible to recordthe information in a good condition, onto the multilayer typeinformation recording medium, regardless of its recording state.

A second embodiment of the information recording medium of the presentinvention is an information recording medium, provided with a pluralityof recording layers to record therein information by irradiating theinformation recording medium with laser light for recording, and havinga first test writing area in which the information is recorded inanother recording layer out of the plurality of recording layers and asecond test writing area in which the information is not recorded in theanother recording layer, in order to obtain a preferable irradiationcondition of the laser light which is preferable to one recording layerin which the information is scheduled to be recorded, out of theplurality of recording layers.

According to the second embodiment of the information recording mediumof the present invention, one of the plurality of recording layers,which are stacked or laminated on one side of a substrate, i.e., whichconstitute the multilayer type information recording medium, such as amultilayer type or dual layer or multiple layer type optical disc, forexample, has the first test writing area in which the information isrecorded in another recording layer and the second test writing area inwhich the information is not recorded in the another recording layer.

Since there are provided the first and second test writing areas, uponthe recording thereof, performed by the information recording apparatus,such as an optical disc recorder, test writing is performed into theboth first and second test writing areas, as occasion demands. Forexample, the OPC is performed. Then, on the basis of the test writingresult, it is possible to irradiate the laser light in the preferableirradiation condition, regardless of the recording state, which isrecorded or unrecorded or the like, of another recording layer, such asthe recording layer located on the front as viewed from the irradiationside of the laser light. By this, it is possible to record theinformation in a good condition, onto the multilayer type informationrecording medium, regardless of its recording state.

These effects and other advantages of the present invention become moreapparent from the following examples.

As explained above, according to the embodiment of the informationrecording apparatus in the present invention, it is provided with: thesetting device; and the irradiating device, and according to theembodiment of the information recording method in the present invention,it is provided with: the setting process; and the irradiating processTherefore, it is possible to record the information in a good condition,onto the multilayer type information recording medium, regardless of itsrecording state. Moreover, according to the first or second embodimentof the information recording medium of the present invention, it isprovided with: the management information area; or the test writingarea. Therefore, it is possible to record the information in a goodcondition, onto the multilayer type information recording medium,regardless of its recording state.

EXAMPLES

An optical disc according to the example of the information recordingmedium will be discussed in detail, with reference to FIG. 1 to FIG. 5.

At first, with reference to FIG. 1, the basic structure of the opticaldisc in the example will be discussed. FIG. 1 shows the basic structureof the optical disc according to the example of the informationrecording medium of the present invention, wherein the upper part is asubstantial plan view showing the optical disc having a plurality ofareas and the corresponding lower part is a schematic conceptual viewshowing a recording area structure in the radial direction.

As shown in FIG. 1, an optical disc 100 has a recording surface on adisc main body with a diameter of about 12 cm, as is a DVD. On therecording surface, the optical disc 100 is provided with: a lead-in area101; a data zone 102; and a lead-out area 103, which are associated withthe example, from the inner circumferential side to the outercircumferential side, with a center hole 1 as the center. Then, in eachrecording area, a track or tracks 10, such as a groove track and a landtrack, are alternately placed, spirally or concentrically, with thecenter hole 1 as the center. On the track 10, data is divided andrecorded by a unit of ECC block 11. The ECC block 11 is a datamanagement unit by a pre-format address in which record information iserror-correctable.

Incidentally, the present invention is not particularly limited to theoptical disc having these three areas. For example, even if the lead-inarea 101 or the lead-out area 103 does not exist, a data structureexplained below can be constructed. Moreover, as described later, thelead-in area 101 or the lead-out area 103 may be further segmentized.

Next, with reference to FIG. 2, the physical structure of the opticaldisc in the example will be explained. More specifically, the opticaldisc 100 in the example is constructed as a two-layer type optical discin which a plurality of data zones 102 or the like area formed in alaminated structure. FIG. 2 is a partially enlarged perspective viewshowing a recording surface of the optical disc according to the exampleof the information recording medium of the present invention.

In FIG. 2, in the example, in the optical disc 100, a first recordinglayer 107 of a phase change type or of an irreversible change recordingtype by heat or the like which constitutes an information recordingsurface is stacked or laminated on (on the lower side of, in FIG. 2) adisc-shaped transparent substrate 106, and a semitransparent reflectivefilm 108 is stacked or laminated thereon (on the lower side in FIG. 2).On the information recording surface which is the surface of the firstrecording layer 107, a groove track GT and a land track LT arealternately formed. Incidentally, upon the recording and thereproduction of the optical disc 100, as shown in FIG. 2, for example,the groove track GT is irradiated with laser light LB through thetransparent substrate 106. For example, upon the recording, byirradiating the laser light LB with a recording laser power, writing bya phase change into the first recording layer 107 or irreversible changerecording by heat is performed, in accordance with the record data. Onthe other hand, upon the reproduction, by irradiating the laser light LBwith a reproduction laser power weaker than the recording laser power,the record data written in the first recording layer 107 is read.

In the example, the groove track GT is wobbled with a certain amplitudeand at a certain spatial frequency. In other words, the groove track GTis wobbled, and the cycle of the wobble 109 is set to a predeterminedvalue. On the land track LT, there is formed an address pit which isreferred to as a land pre-pit LP and which indicate pre-format addressinformation. By virtue of the two addressing (i.e. the wobble 109 andthe land pre-pit LP), it is possible to obtain information necessary fordata recording, such as a recording address, disc rotation controlduring the recording, or generation of a recording clock. Incidentally,it is also possible to record the pre-format address information inadvance, by modulating the wobble 109 of the groove track GT in apredetermined modulation method, such as frequency modulation and phasemodulation.

Particularly in the example, a second recording layer 207 is formed on(on the lower side of, in FIG. 2) the semitransparent reflective film108, and a reflective film 208 is formed thereon (on the lower side inFIG. 2). The second recording layer 207 is constructed such that therecording and reproduction of a phase change type or of an irreversiblechange recording type by heat or the like can be performed byirradiating it with the laser light LB through the transparent substrate106, the first recording layer 107, and the semitransparent reflectivefilm 108, in substantially the same manner of the first recording layer107. The second recording layer 207 and the reflective film 208 may becoated and formed on the transparent substrate 106 on which the firstrecording layer 107 and the semitransparent reflective film 108 or thelike are formed. Alternatively, after coated and formed on differentsubstrates, and the second recording layer 207 and the reflective film208 may be bonded or pasted on the transparent substrate 106.Incidentally, there is provided a transparent middle layer 205 made of atransparent adhesive or the like, between the semitransparent reflectivefilm 108 and the second recording layer 207, as occasion demands, inaccordance with the production method.

Upon the recording/reproduction of such a two-layer type optical disc100, the recording/reproduction in the first recording layer 107 or thesecond recording layer 207 is performed, depending on which recordinglayer has the focus position of laser light LB.

Incidentally, the optical disc 100 in the example is not limited to atwo-layer single sided type, i.e., a dual layer type, as shown in FIG.2, but may be one-layer double sided type, i.e., a double sided type, ora two-layer double sided type, i.e., a dual layer double sided type.Furthermore, the optical disc 100 in the example is not limited to theoptical disc having the two recording layers, as described above, butmay be an optical disc of a multilayer type which has three or morelayers.

Next, with reference to FIG. 3, the data structure of the optical discin the example will be discussed. FIG. 3 is a data structural viewconceptually showing an example of the data structure of the opticaldisc in the example.

As shown in FIG. 3, the optical disc 100 has two recording layers, i.e.,an L0 layer (i.e. a recording layer corresponding to the first recordinglayer 107 in FIG. 1 and FIG. 2) and an L1 layer (i.e. a recording layercorresponding to the second recording layer 207 in FIG. 1 and FIG. 2).

The L0 layer is provided with: a lead-in area 101-0; a data zone 102-0;and a lead-out area 103-0. The lead-in area 101-0 is provided with anOPC (Optimum Power Calibration) area 101A-0 and a management informationrecording area 101B-0, which constitutes one example of the “managementinformation area” of the present invention. In the managementinformation recording area 101B-0, there are recorded (i) preferableinformation 101C-0 upon not-recording, which indicates the preferableirradiation condition of the laser light in the L1 layer if the L0 layeris unrecorded and which constitutes one example of the “preferableirradiation condition information” of the present invention, and (ii)ratio or difference information 11D-0, which constitutes one example ofthe “relationship information” of the present invention. In themanagement information recording area 101B-0, there may be also recordedpreferable information upon recording, which indicates the preferableirradiation condition of the laser light in the L1 layer if the L0 layeris recorded, in place of the ratio or difference information 101D-0.Incidentally, the preferable information 101C-0 upon not-recording andthe ratio or difference information 101D-0 will be discussed later.

On the other hand, the L1 layer is also provided with: a lead-in area101-1; a data zone 102-1; and a lead-out area 103-1. The lead-in area101-1 is provided with an OPC area 101A-1 and a management informationrecording area 101B-1. As in the L0 layer, in the management informationrecording area 101B-1 in the L1 layer, there may be recorded preferableinformation 101C-1 upon not-recording and ratio or differenceinformation 101D-1 (or preferable information upon recording).

The OPC area 101A-0 (101A-1) is an area used in the detection of anoptimum recording laser power (i.e. the calibration of the recordinglaser power). In particular, the OPC area 101A-0 is preferably used forthe detection of the optimum recording laser power in the L0 layer, andthe OPC area 101A-1 is preferably used for the detection of the optimumrecording laser power in the L1 layer. For example, after the testwriting of an OPC pattern is completed, the test-written OPC pattern isreproduced, and the reproduced OPC pattern is subsequently sampled, tothereby detect the optimum recording laser power. Moreover, it is alsoallowed to record the value of the optimum recording laser powerobtained by the OPC.

Next, the type of the data of the land pre-pits which are recorded inthe lead-in area in the L1 layer of the optical disc in the example willbe discussed. FIG. 4 is a table showing the classification of data ofland pre-pits recorded in the lead-in area in the L1 layer of theoptical disc in the example. Incidentally, the table shows a fieldidentification number (Field ID), information to be recorded (Content),and a recording location (Location) from the left column.

As shown in FIG. 4, the data of the land pre-pits which are recorded inthe lead-in area in the L1 layer, which constitutes one example of the“management information area” of the present invention, is classifiedinto ID#0 to ID#13 by the Field ID.

In the land pre-pit identified by ID#0, information about an ECC (ErrorCorrecting Code) block address is recorded. This land pre-pit is locatedin all the recording areas of the optical disc. Here, the ECC blockaddress is an error-correctable recording unit, i.e., positioninformation based on the ECC block.

In the land pre-pit identified by ID#1, information, such as extendedinformation, for identifying the L1 layer, is recorded. The land pre-pitis located in the lead-in area of the optical disc.

In the land pre-pit identified by D#2, strategy information for 1X inthe case where the L0 layer is unrecorded, which constitutes one exampleof the preferable irradiation condition information of the presentinvention, is recorded. The land pre-pit is located in the lead-in areaof the optical disc.

In the land pre-pits identified by ID#3 and ID#4, information about aproduction identification number for identifying the optical disc isrecorded. The land pre-pits are located in the lead-in area of theoptical disc.

In the land pre-pit identified by ID#5, strategy information for 1X inthe case where the L0 layer is recorded, which constitutes one exampleof the preferable irradiation condition information of the presentinvention, is recorded. The land pre-pit is located in the lead-in areaof the optical disc.

In the land pre-pit identified by ID#6, strategy information for 2X inthe case where the L0 layer is unrecorded, which constitutes one exampleof the preferable irradiation condition information of the presentinvention, is recorded. The land pre-pit is located in the lead-in areaof the optical disc. In the land pre-pit identified by ID#7, strategyinformation for 2X in the case where the L0 layer is recorded, whichconstitutes one example of the preferable irradiation conditioninformation of the present invention, is recorded. The land pre-pit islocated in the lead-in area of the optical disc.

In the land pre-pits identified by D#8 to ID#10, strategy informationfor 4X in the case where the L0 layer is unrecorded, which constitutesone example of the preferable irradiation condition information of thepresent invention, is recorded. The land pre-pits are located in thelead-in area of the optical disc.

In the land pre-pits identified by ID# 1 to ID# 13, strategy informationfor 4X in the case where the L0 layer is recorded, which constitutes oneexample of the preferable irradiation condition information of thepresent invention, is recorded. The land pre-pits are located in thelead-in area of the optical disc.

Next, with reference to FIG. 5, the arrangement in the lead-in area ofthe land pre-pits in the L1 layer of the optical disc in the examplewill be discussed. FIG. 5 is a table showing the arrangement and the ECCblock address in the lead-in area of the land pre-pits in the L1 layerof the optical disc in the example. Incidentally, this table shows thefield identification number (Field ID), the recording location(Location), and the ECC block address, from the left column.

As shown in FIG. 5, the land pre-pits identified by the fieldidentification numbers of ID#1 to ID #13 or ID#0 are periodicallyrecorded in the lead-in area in the L1 layer. These land pre-pits arelocated at ECC block addresses of “FFDD05” to “FFCFFF”, which areexpressed in hexadecimal numeral, for example.

(First Example of Information Recording Apparatus)

Next, with reference to FIG. 6 to FIG. 10, the first example of theinformation recording apparatus in the present invention will bediscussed.

At first, with reference to FIG. 6 and FIG. 7, a basic principle ofsetting the preferable irradiation condition in the first example of theinformation recording apparatus in the present invention will bediscussed. FIG. 6 and FIG. 7 are schematic conceptual views showing arelationship between laser light for recording and the optical disc, inthe case where the L0 layer is unrecorded and in the case where the L0layer is recorded, on the optical disc in the first example of theinformation recording apparatus of the present invention.

As shown in FIG. 6 and FIG. 7, the optical disc 100 in the exampleincludes the L0 layer as the first recording layer, and the L1 layer asthe second recording layer shown in FIG. 2. Then, the laser light forrecording is irradiated from the side of a not-illustrated substrate,i.e., from the lower to the upper side in FIG. 6 and FIG. 7, by anot-illustrated optical pickup of the information recording apparatus,and the focal distance thereof or the like is controlled. At the sametime, the travel distance and direction in the radial direction of theoptical disc are controlled. By this, the data is recorded into eachrecording layer. Moreover, if the information recording apparatusfunctions as an information reproducing apparatus, the recorded data isreproduced.

As shown in FIG. 6, if the L0 layer is unrecorded, the unrecorded stateof the L0 layer is detected by scanning performed by a CPU, an LDdriver, and an optical pickup or the like, which constitute one exampleof the “setting device” of the present invention. Simultaneously, afirst recording pulse which defines one example of the “preferableirradiation condition” of the present invention is set in the datarecording. The details of the first recording pulse will be discussedlater.

As shown in FIG. 7, if the L0 layer is recorded, the recorded state ofthe L0 layer is detected by scanning performed by the CPU, the LDdriver, and the optical pickup or the like. Simultaneously, a secondrecording pulse which defines another example of the “preferableirradiation condition” of the present invention is set in the datarecording. The details of the second recording pulse will be discussedlater.

As seen from FIG. 6 and FIG. 7, if transmittance in a portion of the L0layer located on the optical path of the laser light with which the L1layer is irradiated decreases because the L0 layer is already recorded(refer to FIG. 7), the amount of the light reaching the L1 layer and theamount of the light detected from the L1 layer decrease. In other words,if the transmittance in a portion of the L0 layer located on the opticalpath of the laser light with which the L1 layer is irradiated does notdecrease because the L0 layer is unrecorded (refer to FIG. 6), theamount of the light reaching the L1 layer and the amount of the lightdetected from the L1 layer relatively increase. Therefore, as explainedbelow, the example is to compensate the increase/decrease in the amountof the light reaching the L1 layer according to the recording orunrecording in the L0 layer, basically on the light source side of thelaser light.

Next, with reference to FIG. 8 to FIG. 10, a specific example of thepreferable irradiation condition according to the first example of theinformation recording apparatus of the present invention will bediscussed.

Particularly in the first example, the preferable irradiation conditioninformation as illustrated in FIG. 3 to FIG. 5 is not necessarilyrecorded on the optical disc 100 side, and is stored in a memorydisposed on the information recording apparatus side in the example. Thepreferable irradiation condition information is read if necessary, andused for the setting of the preferable information condition.Incidentally, with respect to the preferable irradiation conditioninformation, what is obtained by performing the OPC process for theoptical disc 100 by the information recording apparatus may be stored inthe memory disposed on the information recording apparatus side, in aform that the preferable irradiation condition information correspondsto the disc identification number of the optical disc 100, for example.Alternatively, the preferable irradiation condition information recordedon the optical disc 100 side, as illustrated in FIG. 3 to FIG. 5, may beread and stored in the memory disposed on the information recordingapparatus side.

At first, with reference to FIG. 8, an explanation will be given to thelaser of a pulse type (hereinafter referred to a “recording pulse”)characterized by pulse intensity which is one specific example of thepreferable irradiation condition according to the first example of theinformation recording apparatus of the present invention. FIG. 8 is agraph showing the recording pulse characterized by the pulse intensitywhich is one specific example of the preferable irradiation conditionaccording to the first example of the information recording apparatus ofthe present invention, wherein the vertical axis shows the intensity(power) of the recording pulse and the horizontal axis shows time.

As shown in FIG. 8, the recording pulse is provided with: a first toppulse top; a plurality of multi pulses mp in which the irradiation timeis divided into shorter times; and a cooling pulse c1. Incidentally, itis defined such that a time interval in which the top pulse top isirradiated is Ttop, a time interval in which the multi pulse mp isirradiated is Tmp, and a time interval in which the cooling pulse c1 isirradiated is Tc1.

As shown in FIG. 8, in the preferable irradiation condition, a change inthe L0 layer from the unrecorded state to the recorded state isdetected, under the control of a CPU or the like, in the recording inthe L1 layer. For example, the setting is changed from a first recordingpulse Lw1 to a second recording pulse Lw2.

More specifically, at first, in the first recording pulse Lw1, the toppulse top and the multi pulse mp are set to a recording laser power of8.0 (mW).

Then, in the second recording pulse Lw2, the setting of the multi pulsemp is changed to a recording laser power of 12.0 (mW), for example. Byincreasing the pulse intensity as described above, it is possible toeliminate influences, such as the decrease in light transmittance causedby that the L0 layer is already recorded.

Incidentally, in a time interval in which the recording pulse is notirradiated with the power of the laser for recording, i.e. a down time,the power is set to a bias laser power, which is weaker than an erasinglaser power of 0.6 (mW), for example. The cooling pulse c1 is providedin the end of the recording pulse, and set to the bias laser power, aswith the down time. Moreover, the time interval Tmp in which the multipulse mp is irradiated is equally set.

As described above, it is possible to eliminate the influences, such asthe decrease in light transmittance, by setting the preferableirradiation condition, such as the pulse intensity and recordingstrategy, in accordance with the recording state of the L0 layer, in therecording in the L1 layer, under the control of the CPU or the like.

Next, with reference to FIG. 9, an explanation will be given to arecording pulse characterized by a pulse width which is another specificexample of the preferable irradiation condition according to the firstexample of the information recording apparatus of the present invention.FIG. 9 is a graph showing the recording pulse characterized by the pulsewidth which is another specific example of the preferable irradiationcondition according to the first example of the information recordingapparatus of the present invention, wherein the vertical axis and thehorizontal axis are the same as those of the above-mentioned explanationin FIG. 8. Moreover, the definition of the top pulse top, the multipulse mp, and the cooling pulse or the like is also the same as that ofthe explanation in FIG. 8.

As shown in FIG. 9, in the preferable irradiation condition, a change inthe L0 layer from the unrecorded state to the recorded state isdetected, under the control of the CPU or the like, in the recording inthe L1 layer. For example, the setting is changed from the firstrecording pulse Lw1 to the second recording pulse Lw2.

More specifically, at first, in the first recording pulse Lw1, the toppulse top and the multi pulse mp are set to a recording power of 8.0(mW), for example, and set to reduce the pulse width.

Then, in the second recording pulse Lw2, the setting is changed toincrease the time interval Tmp in which the multi pulse mp isirradiated, i.e. to increase the pulse width. Incidentally, theintensity of the multi pulse mp may be 8.0 (mW), for example, as in thefirst recording pulse Lw1.

As described above, it is possible to eliminate the influences, such asthe decrease in light transmittance, by setting the preferableirradiation condition, such as the pulse width and the recordingstrategy, in accordance with the recording state of the L0 layer, in therecording in the L1 layer, under the control of the CPU or the like.

Next, with reference to FIG. 10, an explanation will be given to a graphshowing a recording pulse characterized by the pulse intensity and thepulse width which are another specific example of the preferableirradiation condition according to the first example of the informationrecording apparatus of the present invention. FIG. 10 is a graph showinga recording pulse characterized by the pulse intensity and the pulsewidth which are another specific example of the preferable irradiationcondition according to the first example of the information recordingapparatus of the present invention, wherein the vertical axis and thehorizontal axis are the same as those of the above-mentioned explanationin FIG. 8. Moreover, the definition of the top pulse top, the multipulse mp, and the cooling pulse or the like is also the same as that ofthe explanation in FIG. 8.

As shown in FIG. 10, in the preferable irradiation condition, a gradualchange in the L0 layer from the unrecorded state to the recorded stateis detected, under the control of the CPU or the like, in the recordingin the L1 layer. For example, the setting is changed in stages from thefirst recording pulse Lw1 to the second recording pulse Lw2.

More specifically, at first, in the first recording pulse Lw1, the toppulse top and the multi pulse mp are set to a recording power of 8.0(mW), for example, and set to reduce the pulse width.

Then, in the second recording pulse Lw2, the setting is changed toincrease the recording laser power in stages, i.e. to increase the pulseintensity in stages. Simultaneously, the setting is changed increase thetime interval Tmp in stages in which the multi pulse mp is irradiated,i.e. to increase the pulse width in stages.

As described above, it is possible to eliminate the influences, such asthe decrease in light transmittance, by setting the preferableirradiation condition, such as the pulse intensity, the pulse width, thepulse shape and the recording strategy, in accordance with the recordingstate of the L0 layer, in the recording in the L1 layer, under thecontrol of the CPU or the like.

(Second Example of Information Recording Apparatus)

Next, with reference to FIG. 11 and FIG. 12, the second example of theinformation recording apparatus of the present invention will bediscussed. FIG. 11 and FIG. 12 are schematic conceptual views showingthe relationship between the laser light for recording and the opticaldisc in the case where the L0 layer is unrecorded and in the case wherethe L0 layer is recorded, on the optical disc according to a secondexample of the information recording apparatus of the present invention.

The basic principle in which the preferable irradiation condition is setin the second example of the information recording apparatus is the sameas that of the first example of the information recording apparatus ofthe present invention which is explained with reference to FIG. 6 toFIG. 10 described above.

Particularly in the second example, the preferable irradiation conditioninformation as illustrated in FIG. 3 to FIG. 5 is recorded on theoptical disc 100 side. The preferable irradiation condition informationis read if necessary, and used for the setting of the preferableirradiation condition. Incidentally, the preferable irradiationcondition information may be read after the optical disc 100 is loadedinto the information recording apparatus, stored in a memory disposed onthe information recording apparatus side, and read, if necessary, fromthe memory.

As shown in FIG. 11, in the second example of the information recordingapparatus, if the optical disc 100 is loaded or mounted, a seekoperation is performed by the optical pickup or the like, under thecontrol of the CPU or the like, to thereby obtain various managementinformation required for the recording operation with respect to theoptical disc 100. More specifically, the preferable information 10C-0upon not-recording in the L1 layer if the L0 layer is unrecorded, whichconstitutes one example of the “preferable irradiation conditioninformation” of the present invention recorded in the managementinformation recording area 11B-0, is obtained. At the same time, theratio or difference information 101D-0, which constitutes one example ofthe “relationship information” of the present invention, is alsoobtained. Here, the ratio or difference information 101D-0 is numericalinformation which represents a ratio or difference between (i) thepreferable information 101C-0 upon not-recording and (ii) the preferableirradiation condition information in the L1 layer in the case where theL0 layer is recorded. Incidentally, the preferable information 101C-0upon not-recording and the ratio or difference information 101D-0 may berecorded in the L1 layer.

As described above, if the L0 layer is unrecorded, the preferableirradiation condition is set on the basis of the preferable information101C-0 upon not-recording. For example, the first recording pulse Lw1with pulse intensity of 10.0 (mW) is irradiated to the L1 layer.

On the other hand, as shown in FIG. 12, if the L0 layer is recorded, thepreferable irradiation condition information in the L1 layer in the casewhere the L0 layer is recorded is calculated by multiplication oraddition of the preferable information 101C-0 upon not-recording and theratio or difference information 101D-0, to thereby set the preferableirradiation condition. For example, if the ratio or differenceinformation 101D-0 is “1.2” or “2.0 (mW)”, the pulse intensity value of10.0 (mW) which is set on the basis of the preferable information 101C-0upon not-recording, is multiplied by or added to the ratio or differenceinformation 011D-0, which results in 10.0 (mW)×1.2=12.0 (mW) or 10.0(mW)+2.0 (mW)=12.0 (mW).

As described above, if the L0 layer is recorded, the preferableirradiation condition is set on the basis of the preferable information101C-0 upon not-recording and the ratio or difference information101D-0. For example, the second recording pulse Lw2 with pulse intensityof 12.0 (mW) is irradiated to the L1 layer.

(Information Recording/Reproducing Apparatus)

Next, with reference to FIG. 13, the structure and the operation of theinformation recording apparatus in the present invention will bediscussed. Particularly, in the example, the information recordingapparatus of the present invention is applied to an informationrecording/reproducing apparatus for the optical disc described above.

At first, with reference to FIG. 13, the structure of an informationrecording/reproducing apparatus 300 according to the example of theinformation recording apparatus of the present invention will bediscussed. FIG. 13 is a block diagram showing the informationrecording/reproducing apparatus 300 according to the example of thepresent invention. Incidentally, the information recording/reproducingapparatus 300 has a function of recording the record data onto theoptical disc 100 and a function of reproducing the record data recordedon the optical disc 100.

With reference to FIG. 13, the inner structure of the informationrecording/reproducing apparatus 300 will be discussed. The informationrecording/reproducing apparatus 300 is an apparatus for recording theinformation onto the optical disc 100 and reading the informationrecorded on the optical disc 100, under the control of a CPU 354.

The information recording/reproducing apparatus 300 is provided with:the optical disc 100; a spindle motor 351; an optical pickup 352; asignal recording/reproducing device 353; the CPU (drive control device)354; a memory 355; a data input/output control device 306; an operationbutton 310; a display panel 311; and a bus 357.

The spindle motor 351 is intended to rotate and stop the optical disc100, and operates upon accessing the optical disc. More specifically,the spindle motor 351 is constructed to rotate and stop the optical disc100 at a predetermined speed, under spindle servo from a not-illustratedservo unit or the like.

The optical pickup 352 is intended to perform the recording/reproductionwith respect to the optical disc 100, and is provided with a laserdevice, a lens, and the like. More specifically, the optical pickup 352irradiates the optical disc 100 with a light beam, such as a laser beam,as reading light with a first power upon reproduction, and as writinglight with a second power upon recording, with it modulated. Inparticular, the optical pickup 352 constitutes one example of the“irradiating device” of the present invention.

The signal recording/reproducing device 353 controls the spindle motor351 and the optical pickup 352, to thereby perform therecording/reproduction with respect to the optical disc 100. Morespecifically, the signal recording/reproducing device 352 is providedwith: a laser diode (LD) driver; a head amplifier; and the like, forexample. The laser diode driver (LD driver) drives a not-illustratedsemiconductor laser device located in the optical pickup 301. The headamplifier amplifies the output signal of the optical pickup 352, i.e.the reflective light of a light beam, and outputs the amplified signal.

Particularly in the example, the signal recording/reproducing device 353sets the preferable irradiation condition, such as the pulse intensity,the pulse width, the pulse shape, and the recording strategy, inaccordance with the recording state of the L0 layer, in the recording inthe L1 layer, together with the CPU 354 or the like.

The memory 355 is used in the whole data processing and the OPC processor the like on the information recording/reproducing apparatus 300,including a buffer area for the record/reproduction data, an area usedas an intermediate buffer when data is converted into the data that canbe used on the signal recording/reproducing device 353, and the like.Moreover, the memory 355 is provided with: a ROM area into which aprogram for performing an operation as recording equipment is stored; abuffer for compression/decompression of video data; a RAM area intowhich a parameter required for a program operation is stored; and thelike.

Particularly in the example, the memory 355 constitutes one example ofthe “storing device” of the present invention. In the memory 355, the“preferable irradiation condition information”, the “relationshipinformation”, or the “table information” or the like of the presentinvention is stored.

The CPU (drive control device) 354 is connected to the signalrecording/reproducing device 353 and the memory 355 through the bus 357,and controls the entire information recording/reproducing apparatus 300by giving an instruction to each controlling device. Normally, softwarefor operating the CPU 354 is stored in the memory 355. In particular,the CPU 354 constitutes one example of the “setting device” and the“judging device” or the like of the present invention.

The data input/output control device 306 controls the input/output ofthe data from the exterior with respect to the informationrecording/reproducing apparatus 300, to thereby perform storage to andexport from the data buffer on the memory 355. If the input/output ofthe data is a video signal, the data input/output control device 306compresses (encodes) the data received from the exterior into a MPEGformat upon the data input, and outputs it to the memory 355. Moreover,the data input/output control device 306 decompresses (decodes) the datain the MPEG format received from the memory 355, and outputs it to theexterior.

The operation control device 307 receives an operation instruction andperforms display with respect to the information recording/reproducingapparatus 300, and transmits an instruction by the operation button 310,such as an instruction to record or reproduce, to the CPU 354. Moreover,the operation control device 307 outputs the operational state of theinformation recording/reproducing apparatus 300, such as duringrecording and during reproduction, to the display panel 310, such as afluorescent tube.

One example of the information recording/reproducing apparatus 300, asexplained above, is recorder equipment for recording and reproducingvideo images in household equipment. The recorder equipment records avideo signal from a broadcast reception tuner and an external connectionterminal, onto a disc, and outputs the video signal reproduced from thedisc to external display equipment, such as a television. The operationas the recorder equipment is performed by executing a program stored inthe memory 355, on the CPU 354.

(Flow of Recording Operation performed by Information RecordingApparatus)

Next, with reference to FIG. 14, a flow of the recording operation ofthe information recording apparatus for the optical disc in the exampleof the present invention will be discussed. FIG. 14 is a flowchartshowing the recording operation of the optical disc by the informationrecording apparatus according to the example of the present invention.

In FIG. 14, at first, if the optical disc 100 is loaded, the seekoperation is performed by the optical pickup 352, under the control ofthe CPU 354, to obtain various management information required for therecording process with respect to the optical disc 100. On the basis ofthe management information, the recording operation of the data isstarted into the L1 layer of the optical disc 100 by the datainput/output control device 306, in accordance with an instruction fromexterior input equipment or the like, under the control of the CPU 354(step S101).

Then, the optical pickup 352 is displaced in the radial direction to arecording start position in the L1 layer, e.g. to a recording startposition based on a physical address, such as a sector number (stepS102).

Then, the optical pickup 352 is focused on the L0 layer, whilemaintaining the radial position of the recording start position in theL1 layer (step S103).

Then, in the L0 layer, sweeping, i.e. scan, is performed up to the sameradial position as a recording end position to be expected in the L1layer, to thereby detect whether or not the information is recorded orunrecorded by each physical address unit, such as a sector number, whichis one example of the “predetermined area unit” of the present inventionwith respect to the L1 layer, and to store the information which showsthe result of sweeping into the memory 355 or the like which constitutesone example of the “storing device” of the present invention (stepS104). Particularly in the example, space bitmap information or the likewhich constitutes one example of the “table information” of the presentinvention may be collectively stored in the memory 355 or the like.

Then, the optical pickup 352 is focused on the L1 layer and displayed inthe radial direction to the above-mentioned recording start position inthe L1 layer (step S105).

Then, by the CPU 354 or the like, it is judged whether or not theinformation is recorded or unrecorded in the L0 layer at the same radialposition as the recording position in the L1 layer (step S106). If it isnot recorded, i.e. if it is unrecorded (the step S106: No), for example,the first recording pulse is set as the preferable irradiation condition(step S107). In this case, on the basis of the preferable informationupon not-recording which is read from the management informationrecording area 101B-0 of the optical disc 100 (refer to FIG. 3 and FIG.11, etc.), the first recording pulse in the preferable irradiationcondition is set. Alternatively, on the basis of the preferableinformation upon not-recording which is read from the memory 355, thefirst recording pulse in the preferable irradiation condition is set.

On the other hand, if it is recorded (the step S106: Yes), for example,the second recording pulse is set as the preferable irradiationcondition (step S108). In this case, on the basis of the preferableinformation upon not-recording and the ratio or difference informationwhich are read from the management information recording area 101B-0 ofthe optical disc 100 (refer to FIG. 3 and FIG. 11, etc.), the secondrecording pulse in the preferable irradiation condition is set.Alternatively, on the basis of the preferable information uponnot-recording and the ratio or difference information which are readfrom the memory 355, the second recording pulse in the preferableirradiation condition is set.

Then, on the basis of the set preferable irradiation condition, theactual recording operation is started in the L1 layer by the opticalpickup 352 or the like (step S109).

Then, it is judged whether or not it is the recording end position to beexpected in the L1 layer (step S110). Here, if it is not the recordingend position to be expected (the step S110: No), the operational flowreturns to the step S106. The preferable irradiation condition is setfor each recording state of the L0 layer, and the recording operation iscontinued.

On the other hand, if it is the recording end position to be expected(the step S110: Yes), a series of recording operation in the L1 layer isended.

The present invention is not limited to the above-described examples,and various changes may be made, if desired, without departing from theessence or spirit of the invention which can be read from the claims andthe entire specification. An information recording apparatus, aninformation recording method, and an information recording medium, allof which involve such changes, are also intended to be within thetechnical scope of the present invention.

INDUSTRIAL APPLICABILITY

The information recording apparatus, the information recording method,and the information recording medium according to the present inventioncan be applied to a multilayer type optical disc for consumer orindustrial use on which various information can be highly denselyrecorded, and can be applied to a recorder or a player related to theoptical disc. Moreover, they can be applied to an information recordingmedium, an information recording apparatus or the like, which aremounted on or can be connected to various computer equipment forconsumer or industrial use, for example.

1.-15. (canceled)
 16. An information recording apparatus for recordinginformation onto an information recording medium by irradiating theinformation recording medium with laser light for recording, theinformation recording medium comprising: (i) recording layers in anorder of a first recording layer and a second recording layer from anirradiation side of the laser light; (ii) a management information areain which a ratio information which indicates a ratio between (ii-1) afirst recording power of the laser light irradiated in the secondrecording layer, which is transmitted through an unrecorded area of thefirst recording layer, and (ii-2) a second recording power of the laserlight irradiated in the second recording layer, which is transmittedthrough a recorded area of the first recording layer, is recorded; and(iii) a recording power management area in which a recording power valueinformation which indicates a value of the first recording power or thesecond recording power is recorded, said information recording apparatuscomprising: a reading device for reading the ratio information recordedin the management information area and the recording power valueinformation recorded in the recording power management area; a settingdevice for setting the recording power of the laser light on the basisof the ratio information and the recording power value information readby said reading device; and an irradiating device for irradiating thesecond recording layer with the laser light with the recording power setby said setting device.
 17. The information recording apparatusaccording to claim 16, wherein said information recording apparatusfurther comprises a judging device for judging whether the firstrecording layer is unrecorded or recorded, and said setting device setsthe recording power, in accordance with a judgment result by saidjudging device.
 18. The information recording apparatus according toclaim 17, wherein said judging device judges whether or not the firstrecording layer is unrecorded or recorded, by each predetermined areaunit, by collectively scanning recording areas in the first recordinglayer.
 19. The information recording apparatus according to claim 17,wherein said judging device judges whether or not the first recordinglayer is unrecorded or recorded, by referring to table information whichindicates whether or not the another recording layer is unrecorded orrecorded, by each predetermined area unit in recording areas in theanother recording layer.
 20. An information recording method ofrecording information onto an information recording medium byirradiating the information recording medium with laser light forrecording, the information recording medium comprising: (i) recordinglayers in an order of a first recording layer and a second recordinglayer from an irradiation side of the laser light; (ii) a managementinformation area in which a ratio information which indicates a ratiobetween (ii-1) a first recording power of the laser light irradiated inthe second recording layer, which is transmitted through an unrecordedarea of the first recording layer, and (ii-2) a second recording powerof the laser light irradiated in the second recording layer, which istransmitted through a recorded area of the first recording layer, isrecorded; and (iii) a recording power management area in which arecording power value information which indicates a value of the firstrecording power or the second recording power is recorded, saidinformation recording method comprising: a reading process of readingthe ratio information recorded in the management information area andthe recording power value information recorded in the recording powermanagement area; a setting process of setting the recording power of thelaser light on the basis of the ratio information and the recordingpower value information read by said reading process; and an irradiatingprocess of irradiating the second recording layer with the laser lightwith the recording power set by said setting process.
 21. An informationrecording medium comprising: recording layers in an order of a firstrecording layer and a second recording layer from an irradiation side ofthe laser light, and a management information area in which a ratioinformation which indicates a ratio between (ii-1) a first recordingpower of the laser light irradiated in the second recording layer, whichis transmitted through an unrecorded area of the first recording layer,and (ii-2) a second recording power of the laser light irradiated in thesecond recording layer, which is transmitted through a recorded area ofthe first recording layer, is recorded.
 22. The information recordingmedium according to claim 21, wherein the recording power is pulseintensity.
 23. The information recording medium according to claim 21,wherein the management information area is in a lead-in area.
 24. Theinformation recording medium according to claim 21, wherein the ratioinformation is recorded in advance as pre-format information.